<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>demo1</title>
</head>
<body>
<div id="app-4">
    <ol>
        <li v-for="(item, index) in items " :key="index" v-if="item.isshow">
            {{ parentMsg }} {{ index+1 }}:{{ item.text }}
        </li>
    </ol>
    <button v-on:click="addData">addData</button>
</div>
<script src="vue.js"></script>
<script>
    var app4 = new Vue({
        el: '#app-4',
        data: {
            parentMsg:"Message",
            items: [
                { text: 'Learn JavaScript' ,isshow:false},
                { text: 'Learn Vue' ,isshow:true},
                { text: 'Build something awesome' ,isshow:true}
            ]
        },
        methods: {
            addData: function () {
                this.items.push({text: "Welcome 2 LZUGIS", isshow:true})
            }
        }
    });
</script>
</body>
</html>